My partner and I stayed at Thierry's apartment in Bangkok and it was our first time in Thailand. Thierry was very nice and warm from the beginning of our correspondence and he was attentive to our concerns. After arriving, his mother-in-law took good care of us and we had everything we needed in the apartment. There're towels, air-conditioning, cable TV, Wi-Fi, and a kitchen (if you plan to buy street food to keep as late-night snacks, the fridge and microwave oven come in handy) His apartment is located in between the Sanam Pao and Ari BTS stations. We usually used Sanam Pao when we traveled to Victory Monument (boat noodles!) and Ratchathewi (Platinum Mall!) because it's slightly nearer if you went out through the back of the building. We'd only walk towards the Ari BTS for dinner to cross over to Phahon Yothin 7 (aka Soi Ari). There's this small restaurant called Boathouse on the left (written only on the front of their menus) along Soi 7 as you walk in that has its kitchen outside and wooden tables inside which was a real gem; the dishes were cheap (60-70 baht each) and the Coconut Soup with Chicken is sooo good! We went back there twice during our trip.
We recommend anyone staying in the area to go look for Puritan which is in Soi 5 because the place is wonderfully decorated and the cakes are LOW-FAT.
I'd also recommend walking around Soi Ari in the morning for breakfast because there's a lot of street food stalls out at that time as well.
For those who have read about After You, you'd be glad to know there's a branch in La Villa Market which is next to the Ari BTS. We saved that for last and the Shibuya Honey Toast really is every bit as amazing as the reviews say.
There's also a laundromat nearby (we didn't use it) if that's something you need. The reception downstairs could call guests a cab as well but at a cost of 20 baht each trip. Be sure to tell them in advance though, it may take them awhile. We gave them an hour's notice.
For those who would be taking cabs from the airport and you're concerned you wouldn't be able to direct the cab driver to the apartment building, you can buy a SIM card at the airport and then give Thierry's mother-in-law a call and she will help you direct the cab driver.
Hope all this helps! :)